1. Field of the Invention
The present invention relates to a communication device and a method used in a wireless communication system, and more particularly, to a communication device and a method of handling a failure in communications with multiple base stations in a wireless communication system.
2. Description of the Prior Art
A long-term evolution (LTE)-advanced (LTE-A) system, as its name implies, is an evolution of the LTE system. The LTE-A system includes advanced techniques, such as carrier aggregation (CA), coordinated multipoint (CoMP) transmissions/reception, uplink (UL) multiple-input multiple-output (UL-MIMO), licensed-assisted access (LAA) using LTE, dual connectivity, etc.
A UE may receive/transmit packets (e.g., transport blocks (TBs)) from/to two eNBs, when the UE is configured to dually connect to the eNBs in the dual connectivity. One of the eNBs is a master eNB (MeNB) of the UE, and the other is a secondary eNB (SeNB) of the UE in the dual connectivity. When the UE detects a radio link failure occurs in a primary cell (PCell) (e.g., of the MeNB) in a master cell group (MCG), the UE may perform a RRC connection reestablishment procedure in response to the radio link failure. At the same time, the UE may also perform a SCG failure information procedure or a reporting of a radio link failure occurred on a primary secondary cell (PSCell) (e.g., of the SeNB) in the SCG. The operations (e.g., transmissions/receptions of related messages) of the procedures may collide, and wrong responses may be generated by the UE and/or the eNBs. Thus, handling of failure(s) related to multiple eNBs is an important problem to be solved.